Diagnostic shifts in bipolar disorder ‘raise concerns’

Diagnostic shifts related to bipolar disorder were common, particularly for other affective disorders, according to results of a longitudinal study published in Journal of Clinical Psychiatry.

“There is a paucity of studies focusing on the diagnostic stability of [bipolar disorder], despite the interest in mental health planning,” Fanny Cegla-Schvartzman, MD, of the department of psychiatry, Jiménez Díaz Foundation University Hospital in Spain, and colleagues wrote. “Most recent studies suggest moderate to high levels of diagnostic stability for [bipolar disorder].

“However, these studies are limited by technical difficulties,” they added.

These difficulties included the use of few evaluation points over limited follow-up periods, which has led to concerns regarding the generalization to longer time periods.

In the current study, the investigators aimed to examine the diagnostic stability of bipolar disorder among psychiatric outpatient consultations. Further, they sought to elucidate the sociodemographic factors that affect this stability.

To do so, they analyzed data from the Cumulative Register of Cases of the Community of Madrid on mental health care center outpatient visits between 1980 and 2009. Patients received diagnoses based on ICD-9/ICD-10 criteria. The researchers measured temporal consistency, or the maintenance of the diagnosis over time, and diagnostic constancy, or the presence of bipolar disorder diagnosis in 75% or more of visits.

A total of 14,557 patients received a bipolar disorder diagnosis for at least one evaluation and had 10 or more visits and 1 year of follow-up. Results showed 3,988 patients received a bipolar diagnosis (prospective consistency = 50.8%) at first evaluation and 5,396 at last evaluation (retrospective consistency = 37.5%). Further, 2,026 received a bipolar disorder diagnosis at their first and last evaluations (prospective consistency = 18.3%).

“The results of this study raise concerns about psychiatric research findings, especially in studies with short follow-up periods for chronic conditions that may not allow enough time to reach an accurate diagnosis or in studies that do not take into account the context,” Cegla-Schvartzman and colleagues wrote.